Solid state power amplifiers are advantageous for their compact size and easy integration into semiconductor circuit components. Unfortunately, methods of manufacture for present day semiconductor power amplifiers require a semiconductor substrate dedicated to power amplifier devices or many processing steps in addition to common semiconductor processing steps for typical semiconductor complementary metal-oxide-semiconductor (CMOS) devices or their variants.
For example, high-end power amplifiers are built in gallium arsenide (GaAs) technologies, which require a GaAs substrate and dedicated processing steps that are not compatible with silicon-based CMOS technologies. As a result, the power amplifiers that utilize GaAs technologies tend to be costly. Middle-range power amplifiers are built in modified silicon germanium bipolar complementary metal-oxide-semiconductor (SiGe BiCMOS) technologies developed for high voltage power applications. Even modified SiGe BiCMOS technologies tend to add its own cost associated with enabling power amplifiers.
While, CMOS devices such as lateral diffusion metal-oxide-semiconductor field effect transistors (LDMOSFETs) have been proposed to provide a silicon based power amplifier devices, enabling power amplifiers in standard CMOS technologies also tends to introduce many new processing steps and device modifications to accommodate the high voltages that the power amplifiers require, thus also increasing the manufacturing cost for the power amplifiers. Specifically, prior art CMOS devices for power applications typically require multiple additional mask sets in addition to the masks required to manufacture standard CMOS devices, which tends to drive the manufacturing cost significantly.
In view of the above, there exists a need for a semiconductor structure that provides high voltage power amplification and requires minimal number of additional mask sets and additional processing steps, and methods of manufacturing the same.
Further, fully depleted devices having a tight control of the current through the channel is known to provide superior performance in MOSFETs. Thus, there exists a need for a MOSFET that provides high voltage power amplification and a tight control of the channel, and methods of manufacturing the same.